Heat exchanger support assembly



Aug. 27, 1968 J, c. MCNABNEY 3,398,786

HEAT EXCHANGER SUPPORT ASSEMBLY Filed Nov. 50, 1966 2 Sheets-Sheet 1 FIG. I

INVENTOR. JOHN MC NABNEY Aug. 27, 1968 J. c. M NABNEY HEAT EXCHANGER SUPPORT ASSEMBLY 2 Sheets-Sheet 2 Filed Nov. 50, 1966 Ill! FIG. 3

IN'VENTOR. JOHN MC NABNEY BY 17km ATTORNEY FIG.7

United States Patent 3,398,786 HEAT EXCHANGER SUPPORT ASSEMBLY John C. McNabney, La Crosse, Wis., assignor to The Trane Company, La Crosse, Wis., a corporation of Wisconsin Filed Nov. 30, 1966, Ser. No. 597,953 1 Claim. (Cl. 16555) ABSTRACT OF THE DISCLOSURE Apparatus for supporting a finned tube heat exchanger in such a way as to permit the noise-free thermal expansion and contraction thereof. A plurality of horizontally extending support arms are mounted at spaced intervals along a wall and are provided with slots in their top surfaces in which plastic bearing elements are snapped-inplace. The heat exchanger tube extends transversely of the support arms and is supported at spaced points along its length by cradle elements, each of which has a base slidably positioned in the plastic bearing elements on one of said support arms.

Background of the invention This invention relates to wall mounted heat exchangers of the finned tube type. Such heat exchangers are conventionally supported adjacent a wall inside of a front cover and are supplied with steam or hot water. Air in a room or zone to be conditioned is heated by convection as it flows over the finned tube between the wall and the front cover. The intermittent passage of steam or hot water through the heat exchanger tube in response to varying demands for heating within the conditioned space causes the tube to alternately expand and contract. As it does so, the tube and the fins mounted on it come into abrasive contact with the tube support arms or brackets normally employed to hold the heat exchange unit in an elevated position above the floor. The scraping of the tube and fins along metal support members employed in the past causes an undesirable noise which becomes particularly disturbing in sleeping quarters. Attempts to overcome the noise problem by using nonmetallic materials in conjunction with the heat exchanger support structure have not met with complete success, either because relatively expensive devices such as plastic sleeves embracing the entire heat exchanger were used, or because the heatexchanger was supported on some type of nonmetallic surface by means of the fins, which, being made of thin, lightweight material, were subject to deformation.

Summary of the invention It is the primary objective of this invention to provide structure which not only properly supports a finned tube heat exchanger but also permits the heat exchanger to move freely and quietly during thermal expansion and contraction. This is accomplished by means of plastic bearing surfaces on which cradle elements embracing the finned tube heat exchanger slide quietly back and forth as the tube expands and contracts.

The bearing surfaces are provided simply and inexpensively in the form of molded or extruded nylon inserts positioned on the top surface of spaced apart support arms which extend under the heat exchanger. Each of the aforementioned cradle elements has a base which slidably engages the nylon inserts on one of the support arms.

According to an advantageous feature of the invention, the plastic bearing means on each support arm have Wall portions which contain the aforementioned cradle elements against lateral movement, as well as a wall portion which overlies the base of one of said cradle elements so as to 3,398,786 Patented Aug. 27, 1968 secure said cradle elements against movement when the heat exchanger is being mounted thereon.

A further unique feature of my invention resides in the manner in which, the aforesaid nylon bearing inserts are secured to horizontal support arms. Each of the support arms is provided with slots through which hooked legs formed on each of the bearing inserts are snapped-inplace.

These and other advantageous features of the invention will become readily apparent as the following description is real in conjunction with the accompanying drawings.

Brie description of the drawings FIGURE 1 is a perspective view of a wall mounted heat exchanger installed on the support structure of the invention.

FIGURE 2 is a front elevation view of the heat exchanger and supporting structure therefor.

FIGURE 3 is a vertical cross-sectional view of the heat exchanger and supporting structure taken along line 33 of FIGURE 2.

FIGURE 4 is a, top view of the support bracket and cradle of FIGURE 3 shown with the heat exchanger re moved.

FIGURE 5 is an enlarged front elevation view, partially in section, of the nylon bearing insert and bracket assembly.

FIGURE 6 is a perspective view of one of the nylon bearing inserts.

FIGURE 7 is a perspective view of an alternative form of bearing insert.

FIGURE 1 illustrates a heat exchanger 1 consisting of a tube 2 and a plurality of spaced apart fins 4 secured thereto mounted adjacent a wall 5 above a floor 3 by my improved support structure. A plurality of brackets 6 are fastened to wall 5 at spaced intervals by lag screws 8 which pass through the vertical wall engaging portion 10 of each bracket. Extending forwardly and outwardly from each bracket 6 and formed as an integral part thereof is a substantially horizontal support arm 12. A U-shaped notch 14 is formed in the outer end of each support arm 12 and serves to positively retain the mating lip 16 extending along the bottom edge of front panel 18. The top, inner edge 20 of front panel 18 is rolled into the form of a U-shaped channel which slips between wall 5 and offset extensions 22 at the top of each bracket vertical portion 10 for firm retention against wall 5. Gasket 24 maintains a seal between edge 20 and wall 5. A damper 26 and actuator 28 therefor are provided to control the flow of heated air into the conditioned space through outlet grill 30.

A plurality of notches 32 are punched in the vertical portion 10 of each of the brackets 6 in order to provide means for attaching supplemental support arms 34 thereto. As is most clearly shown in FIGURES 1 and 3, support arms 34 are each provided with a pair of L-shaped tangs 36 at one end thereof which may be hooked into any horizontally aligned pair of notches 32. A plurality of supplemental support arms 34 may be employed to mount heat exchanger 1 at a desired level above main support arms 12. The arrangement of slots 32 and supplemental support arms 34 is particularly useful for selectively positioning the height of finned tube heat exchanger 1 when steam is being passed therethrough as the heating medium. By mounting adjacent supplemental support arms 34 in successively higher pairs of slots 32, heat exchanger 1 supported across arms 34 will assume an inclined position so as to facilitate the drainage of steam condensate therefrom.

Referring again to FIGURE 1, it will be seen that bracket arms 12 and 34 have a pair of slots 38 and 39 punched in their top surfaces. These slots serve as positioning means for plastic bearing inserts 41 and 42, which may be mounted on either arms 12 or 34. When steam is employed as the heating medium as is the case with respect to the exemplary embodiment shown, supplemental support arms 34 are employed to support heat exchanger 1 in an inclined position, and plastic inserts 41 and 42 are secured to arms 34 as is best shown in FIG- URES 2 through 5. On a hot water heating system, supplemental support arms 34 would not be used, and plastic bearing inserts 41 and 42 would be secured to main support arms 12 on which heat exchanger 1 would then be supported.

Plastic bearing inserts 41 and 42 are identical. One of the inserts is shown on an enlarged scale in FIGURE 6. Each insert consists of a piece of plastic molded to in clude a horizontally extending bearing surface 44 and a vertical wall-portion 46. Retention lip 48 protrudes outwardly from the top of wall portion 46. Allochiral legs 49 and 50 having hooked offsets 52 and 54 at their extremities depend from surface 44. Bearing inserts 41 and 42 are preferably made from nylon molded to the form shown. Other plastic materials such as Teflon may also be used.

As is indicated in FIGURES 2 through 5, a pair of bearing inserts 41, 42 are secured in spaced apart slots 39 in each support arm 34. Bearing elements 41, 42 are retained on support arms 34 by means of hooked legs 49 and 50. Referring now to FIGURE in particular, it will be seen that legs 49 and 50 pass downwardly through slots 39 and that hooked offsets 52 and 54 engage the underside of arm 34. The pliable plastic material from which bearing elements 41, 42 are made permits hooked legs 49 and 50 to be pressed inwardly towards each other and snapped-in-place in slots 39. Shoulder 56 (FIGURE 6) on hearing elements 41, 42 rests on the top surface of support arm 34.

A cradle element generally designated 58 is slidably supported on each of the support arms 34 by means of bearing inserts 41, 42. As is best shown in FIGURES 2, 3 and 4, each cradle element 58 is of generally U-shaped configuration and is comprised of a slotted base 60 from which end walls 62 and 64 angle upwardly and outwardly. End walls 62 and 64 are provided with generally V-shaped notches 66 and 68 which receive tube 2 of heat exchanger 1. The slotted base 60 of each cradle element 58 rides on horizontal bearing surfaces 44 of plastic inserts 41, 42. Vertical wall portions 46 of oppositely disposed hearing inserts 41, 42 engage the opposite edges 70, 71 of base 60 so as to prevent lateral movement of cradles 58. Cradle elements 58 are retained on bearing surfaces 44 by lips 48 on each insert 41, 42, which overlie base 60. This arrangement insures that cradle elements 58 will not be knocked off of bearing inserts 41, 42 when heat exchanger 1 is being installed.

FIGURE 2 illustrates a particular advantage which is achieved by inclining cradle end walls 62 and 64 outwardly. When heat exchanger 1 is installed, the lower edge of one of the fins 4a will contact the lower inside surface of end Wall 64 and the next adjacent outside fin 4b will engage the top outside surface of end wall 64. Adjacent fins 4c and 4d contact the other end wall 62 in the same manner. This fin and cradle arrangement positively prevents relative movement between heat exchange tube 2 and cradles 58. If tube 2 moves in either direction, the fins 4a, 4b, 4c and 4d contacting end walls 62 and 64 will carry cradle element 58 along with tube 2. The possibility of noise being generated by the movement of tube 2 back and forth in cradle notches 66 and 68 is thus eliminated.

An alternative form of plastic bearing element, generally designated 43, is shown in FIGURE 7. The upper portion of bearing element 43 which retains and slidably supports cradles 58 is the same shape as elements 41 and 42. Like reference numerals have been used to designate those portions of element 43 which correspond to identical portions of elements 41 and 42. Thus, bearing element 43 has a horizontal bearing surface 44, a vertical wall portion 46 and a lip 48 which support and contain cradles 58 in the same manner as described above with respect to hearing elements 41 and 42. That portion of element 43 which extends through slots 39 in support arm 34 (or slots 38 in arm 12) has been given a different shape in order that elements 43 may be extruded rather than molded. To this end, a continuous length of plastic material would be extruded to include the upper bearing and retaining surface above described. In addition, the length of plastic extrusion would include a single, downwardly depending leg portion 80. The piece of extruded plastic would then be cut into the desired lengths to form a plurality of inserts or bearing elements 43. Each of the bearing elements 43 would be attached to support arms 34, for example, by inserting leg portion through one of the slots 39 and then striking the bottom of leg 80 with a hot forming tool so as to form a base 82 having hooked offsets 81 and 83. Offsets 81 and 83 would engage the underside of support arm 34 so as to hold bearing elements 43 firmly in place.

As will be readily apparent from the foregoing description, the longitudinal movement of tube 2 as it expands and contracts due to the intermittent flow of steam or hot water therethrough will cause cradle elements 58 to slide back and forth on bearing surfaces 44 of plastic inserts 41, 42. Since the movement of metal cradle bases 60 on plastic bearing inserts 41, 42 will be substantially noise-free, my improved support structure accomplishes the desired result of supporting a heat exchanger adjacent a wall in such a way as to provide for its quiet expansion and contraction. The particular shape of plastic bearing elements 41, 42 and 43, and the easy means provided for their installation on support arms 34 or 12 permits this beneficial result to be achieved in a simple and relatively inexpensive manner.

I claim:

1. Heat transfer apparatus comprising, vertically extending wall members, support arms secured to said wall members, and extending horizontally outwardly therefrom; a plurality of cradles above said support arms, each of said cradles having a base and upwardly extending wall means, a heat exchanger supported on said upwardly extending wall means and comprising a tube having a plurality of fins mounted thereon, said heat exchanger extending generally transversely of said support arms, and plastic bearing means having downwardly extending leg means extending through openings in said support arms, said leg means having means securing them to said support arms, said plastic bearing means having portions extending between said support arms and said cradles to support said cradles spaced from said support arms for movement transverse to said support arms, said plastic bearing means and said cradle member each having ways in sliding engagement to limit said cradle member to substantially translatory movement transversely of said support arms.

References Cited UNITED STATES PATENTS 2,670,935 3/1954 Arnold l6555 2,709,564 5/1955 Stenner 248232 3,152,636 10/1964 Distefano -69 MEYER PERLIN, Primary Examiner.

CHARLES SUKALO, Assistant Examiner. 

